Dry plate rectifier and method of producing same



E K N U R B F Filed June 8, 1937 inventor# Fr-itz Brunke,

H1 Atbom ey.

Patented 'June 25, 1940 azoasr par PLATE nao'rmmn AND Mn'rnon or,

rnonUorNG SAME Fritz Brunke, Berlin-Steglitz, Germany, assigner to General Electric Company, a corporation of New York Application June s, 193i, serial No. 147,105 In l(erxrialiy June 13, 1936 imams. (crus-ass) My invention relates to dry plate rectiiiers and likedevices such as light-sensitivecells, wherein a semi-conductor layer composed, for example, of selenium or comprising selenium is deposited on a base or carrier electrode composed of a suitable material such as aluminum, iron, or nickel. The object of the invention is to provide improved devices `of the above-mentioned type and an improved method of. producing such devices.

Heretofore in the process` of manufacturing a selenium rectifier-and the like cells or elements, which normally include a base or carrier electrode having a selenium semi-conductor layer thereon, and a counter electrode, the selenium layer has usually been applied in liquid form to the material of the relatively thin carrier electrode. In this prior process powdered selenium is placed on the carrier electrode to which heat is supplied from a hot plate upon which the electrr ie is laid, the

'2b selenium then melting; and flowing over the carrier electrode to form a thin-layer thereon. In this method as weil las in other prior methods of forming the semi-conductor layer on the carrier electrede, only a portion of the total surface of the carrier electrode is,utilized for forming 4the semiconductor material thereon,y with a resulting waste of carrier electrode material and an increase in `the -requiredsize and weight of the assembled rectlfiers for a given power.

i 30 In accordance with my present invention a Referring to the drawing, Figs. 1 and 2 are, re-

Spectively, plan and side elevational views of a rectifier base or carrier electrode member having thereon semi-conductor material, in accordance with my invention; and Figs. 3 and e are cross-sectional views on an enlarged scale of rectier units having. respectively, series-connect- 4 ed and parallel connected rectifier cells or elements incorporating thecarrier electrode and semi-conductor elements illustrated in Figs. l and 2.

When the above-described prior method of depositing the semi-'conductor layer on the carrier electrode by melting the selenium thereon is employed, only one side of the latter electrode can be thickness.

covered by the semi-conductor layer, with consequent waste of available carrier electrode surface and material. In accordance with my present invention, and as illustrated in Figs. 1 and 2, semiconductor layers or films i and 2, preferably composed of selenium or comprising selenium, are deposited on both sides of a portion of a sheet of a suitable conductive material, preferably aluminum, the main or carrier electrode portion proper of which is designated by the numeral 3. The semi-conductor layers are formed bythe vvapo'rization process, which includes exposing the. carrier electrode 3 to a vapor of the semiconductor material for such a period of time and under such conditions of ambient temperature and pressure that the resulting films l and 2 are of the desired electrical characteristics and small The films may be deposited on the carrier electrode either simultaneously orin succession.

Since both 'sides of the carrier electrodes are thus provided with semi-conductor layers, therefore in assembling rectifier units employing these double-coatedcarrierelectrodes,counterelectrodes are provided on both sides of the carrier electrode 3 in order to utilize both coated surfaces, one counter electrode being in contact with layer I and the other in contact with layer 2. To aid in assembling rectifier units employing the abovedescribed double-coated carrier electrodes it is of advantage to provide the latter with an extension element or strap t, which may be formed integrally with the carrier electrode proper, 3, as by being stamped in one piece with the portion 3, or which -rnay be joined thereto in any suitable manner, the coating process being so arranged that the extension portion 4 is not covered with the semi-conductor material. The extension element i serves asa current lead-in to the carrier electrode i and, as will be more clearly explained hereinafter, may also serve advantageously as a connection to other elements of the rectier unit.

Referring vto Fig. 3, the series-connected rectiner unit illustrated therein comprises a plurality of rectifier cells or elements each comprising 'a carrier electrode t having semi-conductor layers or films i' and 'i which have been applied to the opposite surfaces of the carrier ,electrode by the -above -described vaporization process, and counter electrodes t and 9 in contact, respectively, with the layers t and l. The cells are insulated from each other by insulating plates I0 andare prei-Y erably mounted in the usual manner on a bolt il which may be of insulating material but which is preferably of metal insulated from the rectifier elements by an insulating sleeve I2. The rectifier cells are connected inscries relation by employing, preferably, the extension elements or straps I3, similai` to the strap above described in connection with Figs. l and 2, to connect any v given carrier electrode, for example, the carrier Velectrode at the left-hand end of Fig. 3, with the counter electrodes of the next succeeding rectier cell of the series.

It will be readily seen that, for a rectifier unit having a given area of carrier electrode surface coated with semi-conductor material, the seriesconnected unit, illustrated in Fig. 3, incorporating the double-coatedcarrier electrodes in ac- 'cordance with the invention, requires only one,

half of the number of carrier electrodes which would necessarily be employed in a conventional unit incorporating carrier electrodes having layer melted to only 'one side thereof.

In the parallel-connected rectifier unit illustrated in Fig. 4, the numeral'M designates the. similar members of a group of carrier electrodes each having semi-conductor layers I5. and I6 which have been deposited by the vaporization process on the opposite sides thereof, the electrodes of the group being connected together preferably by means of extension portions or straps I1. The numeral I8 designates the similar members of a group of counter electrodes connected together by any suitable connection means I9. The group of double-coated carrier electrodes I4 is interleaved with the group of counter electrodes I8 and the interleaved electrodes are preferably mounted in the usual manner on a bolt 20 insulated from the rectifier elements by an insulating sleeve 2l. i

It will be seen that, for a parallel-connected rectifier unit having a given area of carrier electrode surface coated with the semi-conductor material, the unit illustrated in Fig. 4. having a group of double-coated carrier electrodes in accordance with the invention, requires, as compared with a conventional unit having the same area of semi-conductor coated carrier electrode surface but with the carrier-electrodes coatedA on one side only, one half the number of carrier electrodes, only one more than half as many counter electrodes, and no insulation between individual cells or elements of the unit.

It will be readily understood, further, that as required to meet various voltage and current conditions, rectifier cells or elements in accordance with the invention may be arranged partly in parallel and partly in series.

-comprising a perforated portion `tions and that by the appended claims I intendl to cover any such modifications as fall Within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. A dry plate device including a plurality of Y rectifier cells, each of said cells comprising a plate of conductive material having a carrier electrode portion and an extension portion, coatings of semi-conductor material on opposite sides of said carrier electrode portion, a pair of counter electrodes in contact respectively with said oppositely-disposed coatings, said carrier electrode portions and said counter electrodes having openings formed therethrough, clamping means exf tending through said openings, and means including said extension portions to connect said rectifier cells in series along said clamping means.

2. A dry plate device including a group of car rier electrodes connected in parallel, each of said carrier electrodes having coatings of semi-conductor material on opposite sides thereof, and

allel, said group of carrier electrodes'being interleaved between said group of counter electrodes and said coatings being in contact with corresponding surfaces of said counter electrodes.

3. A dry plate device including a plurality of rectifier cells, a mounting bolt, each of said cells comprising a plate of conductive material having a group of counter electrodes connected in para perforated carrier electrode portion insulating- 1y mounted on said bolt and an extension portion, coatings of semi-conductor material on opposite sides of said carrier electrode portion, andI a pair of perforated counter electrodes insulatingly mounted on said bolt and in contact respectively with said oppositely-disposed coatings, and means including said extension portions to connect said rectifier cells in Vseries along said mounting bolt.

4. A dry plate device including a mounting bolt, a group of carrier electrodes each comprising a perforated portion insulatingly mounted on said bolt having coatings of semi-conductor material on opposite sides thereof and an extension portion, said extension portions being lconnected together thereby to connect said carrier electrodes in parallel, and a group of counter electrodes each insulatingly mounted on said bolt and an extension portion, said last-namedeirtension portions being connected together to connect said counter electrodes in parallel, said group of carrier electrodes being interleaved between said group of counter electrodes and said coatings being in contact with mm2 BRUNKE.

v corresponding surfaces of said counter electrode.' 

